Internal pipe wrench

ABSTRACT

An internal pipe wrench to engage in and rotate a length of pipe, consisting of an internally threaded hollow body, a plurality of spherically shaped radially movable gripping members carried by the body and an externally threaded, tapered actuation element threadably interconnected with the body for axial movement with respect thereto in a manner as to engage the gripping members and force them radially outwardly into gripping engagement with the inner wall of the pipe.

United States Patent 11 1 Ehrler Sept. 2, 1975 [54] INTERNAL PIPE WRENCH 2,821,946 2/1958 Goekler 269/48.l

[75] Inventor: Fritz O. Ehrler, Panorama City, 0 Moberg 8 l 2 C H. 1 g a l Primary Examiner-James L. Jones, Jr. [73] Assignee: Auger cop Inc, n rn n Attorney, Agent, or Firm-Whann & McManigal Calif.

[22] Filed: Feb. 14, 1974 [57] ABSTRACT [21] A 1 N 442,441 Aninternal pipe wrench to engage in and rotate a length of pipe, consisting of an internally threaded hollow body, a plurality of spherically shaped radially U-So u s u e u t t t s I I 1 r r externally threaded tapered actuation element thread Fleld of Search interconnected th6 for axial movement with respect thereto in a manner as to engage the grip- [56] References ping members and force them radially outwardly into UNITE A E PATENTS gripping engagement with the inner wall of the pipe. 2,273,982 2/1942 Ostas 81/72 2,811,067 10/1957 Greer 81/72 10 6 Drawmg F'gures PATENTED SEP 2 I975 1 INTERNAL PIPE WRENCH BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to gripping tools for releasably gripping tubular members and more particularly to an internal pipe wrench insertable into the open end of a length of pipe and having gripping members for releasably gripping the inner wall of the pipe to en able rotation of pipe.

2. Discussion of the Prior Art Gripping devices of various construction have been developed in the past with several having gripping members movable by assorted types of camming arrangements into gripping engagement with the inner or outer walls of a tubular member such as a length of pipe. Typically, the gripping members comprise movable jaws provided with tooth-like serrations designed to bite into the walls of the tubing so as to prevent slipping upon relative rotation of the tool. I

As exemplified by the prior art US. Pat. No. 2,273,982 issued to C. A. Ostas, many prior art devices embody gripping members designed for maximum efficiency in a reverse or removal rotation. With rotation sensitive" devices of this type, a rocking action which is often highly effective to break loose a troublesome joint, is impossible. Additionally, devices of this character tend to severely cut and tear the inner wall of the pipe causing undesirable inwardly extending protrusions and areas of structural weakness within the pipe.

The novel and unique apparatus of the present invention avoids the drawbacks of the prior art devices by using gripping members in the form of generally spherically shaped smooth balls which are forced radially into gripping engagement with the wall of the tubing or pipe by means of a tapered actuating member. With this type of gripping member, damage to the wall of the tubing is eliminated and most importantly, the device is not rotation sensitive. Because of the configuration of the gripping members, the pipe can be rotated in either direction with equal gripping efficiency. This feature permits the wrench to be used for both right and left hand thread connections and enables the wrench to be rocked first in one direction and then in the other to break loose corroded and difficult pipe joints.

In addition to the Ostas patent, applicant is aware of the following US. Pat. Nos. which represent the closest art known by applicant and which serve to illustrate the unique nature of the present invention:

It is an object of the present invention to provide a simple and highly efficient gripping tool for gripping the walls of a tubular part such as a length of pipe or the like. One form of the tool of the invention comprises a tool in the form of an internal pipe wrench which consists of a hollow, internally threaded body carrying a plurality of radially outwardly movable, generally spherically shaped gripping members and an externally threaded, tapered actuating member threadably receivable by the body for axial movement with respect thereto into operable engagement with the gripping members in a manner so as to force them radi- 2 ally outwardly into secure gripping engagement with the inner wall of, the tubular part.

More particularly, it is an object of the present invention to provide an internal pipe wrench designed to engage in and rotate for purposes of connection with or removal from mating couplings, short lengths of piping.

It is another object of the invention to provide a wrench of the aforementioned character in which the gripping members are configured so as to securely grip the inner surfaces of the pipe without cutting, tearing or otherwise damaging the pipe.

It is still another object of the invention to provide a device of the type described in the preceding paragraphs which securely grips the inner wall of the pipe in a manner such that the pipe may be rotated with equal efficiency in either direction without slipping.

It is a further object of the invention to provide a device of the class described in which the gripping members only engage the inner walls of the pipe so that the tool can be used effectively to remove the stub section of a pipe which has been broken off in its coupling.

It is a further object of the invention to provide an improved wrench of the indicated species which is simple in construction, embodies a minimum number of moving parts, is easy to operate, is highly durable and reliable, and is inexpensive to produce and maintain.

In summary, the objects of the invention are realized by a gripping tool for gripping tubular objects which includes a hollow body having a wall portion generally annular shaped in cross-section and having a plurality of transverse bores extending therethrough; a plurality of generally spherically shaped gripping members carried within the transverse bores and movable axially thereof; and a tapered actuating member cooperatively associated-with the hollow body and movable relative thereto into operable engagement with the gripping members for moving them within the transverse bores in a radial direction with respect to the body.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of one embodiment of the gripping tool of the invention shown here in the form of an internal pipe wrench adapted to releasably grip the internal surfaces of a length of pipe.

FIG. 2 is an end view of the internal pipe wrench as it would appear looking toward the lower end of the wrench as illustrated in FIG. 1.

FIG. 3 is a cross-sectional view of the gripping tool of this embodiment of the invention taken along lines 3-3 of FIGS. 1 and 4 and for purposes of illustration shown as it would appear when inserted into the open end of an externally threaded section of pipe which has been broken off. In this view, the wrench is shown with the gripping members in a retracted position.

FIG. 4 is a cross-sectional view taken along lines 4--4 of FIG. 3.

FIG. 5 is a view similar to FIG. 3, but showing the wrench as it appears when the gripping members have been moved into gripping engagement with the internal wall of the broken off section of pipe.

FIG. 6 is a cross-sectional view taken along lines 6-6 of FIG. 5.

DESCRIPTION OF ONE FORM OF THE INVENTION Referring to the drawings, the gripping tool of the present invention is shown in the form of an internal pipe wrench having an elongated hollow body portion 12, and an actuating means generally designated by the numeral 14 which is cooperatively associated with the hollow body and movable axially with respect thereto.

Referring to FIGS. 3 and 4, the internal pipe wrench of this form of the invention is receivable into the open end 16 of a length of pipe 18 which is threadably connected with a second length of pipe 20. Although the gripping tool of the invention is useful in threadably connecting any two lengths of threaded pipe, it is particularly useful for removing the stub section of a length of pipe which has been broken off in the manner depicted in the drawings.

The elongated hollow body 12 includes a wall portion 22 which, as shown in FIG. 4, is generally annular shaped in cross-section. Provided near the outer or first end of the wall portion 22 is a plurality of transverse bores 24 extending therethrough. In this form of the invention, the axes of the transverse bores are coplanar and are spaced apart approximately 120. Carried within said transverse bores and movable axially thereof, or radially with respect to the hollow body, is a plurality of spherically shaped gripping members 26.

The elongated hollow body portion 22 has an internally threaded barrel portion 28 disposed proximate its second or outer end. Provided externally of barrel portion 28 are wrench engaging means 30, shown here as a hexagonally shaped head portion, for engagement by a wrench adapted to impart rotational forces to said body.

As best seen in FIG. 3, actuating means 14 is provided in the form of an elongated member receivable within the hollow body and having an externally threaded portion 32 intermediate its first and second ends 34 and 36 respectively. A wrench engaging means 38 shown here as a hexagonally shaped head portion is provided at the upper or second end of the actuating means for engagement by a wrench adapted to impart rotational forces to the actuating means. Formed proximate the inner or first end of the actuating means is a tapered portion 40 which tapers inwardly toward the inner end of the actuating means and is adapted to rollably engage gripping members 26 upon axial movement of the actuating means with respect to the hollow body portion.

In this embodiment of the invention the transverse tapered bores 24 which extend through wall portion 22 taper from an enlarged cross-sectional diameter at a location proximate their inner ends 24a (FIG. 3) to a reduced crosssectional diameter at a location proximate their outer ends 24b. To hold the gripping members 26 within the transverse bores 24 when the wrench is not in use, the transverse bores are formed so that the inner cross-sectional diameter thereof is larger than the major diameter of the gripping members 26 and the outer cross-sectional diameter thereof is smaller than the major diameter of the gripping members 26. Although various numbers of transverse bores and coopcrating gripping members could be used, the arrangement shown in the drawings wherein the axes of the transverse bores are coplanar and spaced apart approximately 120 has proven quite satisfactory for most applications.

As illustrated in FIG. 2, there is provided means carried at the outer or first end of actuating means 14 for engagement with the hollow body 12 for preventing the actuating means from being threadably withdrawn from the hollow body. In this embodiment of the invention, the last-mentioned means is provided in the form of a spring clip 42 which is removably carried within a periphery groove 44 formed proximate the inner or first end of actuating means 14.

OPERATION With the gripping tool in the configuration illustrated in FIG. 3, the wall portion 22 of the hollow body 12 is inserted into the section of pipe which is to be removed. In this form of the invention, there is provided a shoulder 46 defined by a reduced diameter shank portion 48 of hollow body 12 for locating the tool axially of the pipe section 18. Using an appropriate wrench, the actuating means is threaded into barrel portion 28 causing the actuating means or member 15 to move axially inwardly into the hollow body portion. As the actuating means moves inwardly, the tapered portion 40 thereof will rollably engage gripping members 26 and will cause these members to move axially of transverse bores 24 and into gripping engagement with the pipe section 18 as shown in FIG. 5. With the actuating means snugly cinched down to insure a positive gripping contact between the gripping members 26 and the inner wall of pipe section 18, body portion 12 may then be rotated by a wrench which has been suitably interconnected with wrench engaging means 30. Rotation of body 12 will, of course, cause the entire tool to correspondingly rotate. Because the gripping members are securely gripping the inner walls of pipe section 18, this pipe section can be rotated with respect to its mating pipe section 20.

It should be noted that due to the novel configuration of the gripping tool of the invention, it is not rotation sensitive, that is, the gripping member 26 being spherical will grip the inner wall of pipe section 18 with equal efficiency irrespective of the direction of rotation of the tool. This permits the wrench to be turned alternately first in one direction and then in the other. This type of rocking action has proven particularly useful in loosening troublesome connections.

Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims.

I claim:.

1. A gripping tool for gripping tubular objects, comprising:

a. a hollow body adapted to be inserted into an open end of the tubular object, including a wall portion generally annular shaped in cross-section, said wall portion having a plurality of transverse bores extending therethrough;

b. a plurality of generally spherically shaped gripping members carried within said transverse bores and movable axially thereof to protrude outwardly from said wall portion; and

c. actuating means cooperatively associated with said body and movable relative thereto into operable engagement with said gripping members for moving said gripping members within said transverse bores in a radial direction with respect to said body whereby said gripping members are moved into gripping engagement with the tubular object to permit concomitant rotation thereof in either a clockwise or counterclockwise direction.

2. A gripping tool as defined in claim 1 in which said actuation means comprises an elongated member receivable within said hollow body and axially movable relative thereto, said member having an inwardly tapering first end portion generally circular in cross-section at any point and so constructed that the outer surfaces thereof will operably engage said gripping members so as to urge them radially outwardly within the transverse bores upon movement of said actuating means axially of said body.

3. A gripping tool as defined in claim 2 in which said elongated member includes wrench engaging means provided proximate the end opposite the tapered portion thereof for engagement by a wrench adapted to impart rotation to said member.

4. A gripping tool as defined in claim 2 in which said hollow body is internally threaded and in which said elongated member is provided with external threads intermediate its end portions adapted to threadably engage the internally threaded hollow body portion.

5. A gripping tool as defined in claim 2 in which the transversely extending bores taper from an enlarged cross-sectional diameter at a point proximate their inner ends to a reduced cross-sectional diameter at a point proximate their outer ends.

6. A gripping tool as defined in claim 5 in which the cross-sectional diameter of the transverse bores at a point proximate their inner ends is larger than the major diameter of said spherical gripping members and at a point proximate their outer ends is smaller than the major diameter of said spherical gripping members.

7. An internal pipe wrench receivable into the open end of a length of pipe and adapted to releasably grip the internal wall thereof for rotating the pipe to enable its connection with or removal from a mating part, said internal pipe wrench comprising:

a. an elongated hollow body having:

1. an internally threaded barrel portion; 2. an integral shank portion having a wall generally annular in shape at any point along its length; 3. a plurality of transverse, tapered bores extending through said wall, said bores tapering from an enlarged cross-sectional diameter at a location proximate their inner ends to a reduced crosssectional diameter at a location proximate their outer ends; and

4. wrench engaging means disposed externally of said barrel portion for engagement by a wrench adapted to impart rotational forces to said body;

b. a plurality of generally spherically shaped gripping members carried by and movable axially within said transverse bores, said gripping members having a major diameter larger than the reduced crosssectional diameter of the transverse bores; and

c. an elongated actuating means movable axially of said body for urging said gripping members radially outwardly within the transverse bores in said wall, said actuating means having:

1. wrench engaging means proximate one end of said means for engagement by a wrench adapted to impart rotational forces to said actuating means;

2. a tapered portion disposed proximate and tapering inwardly toward the opposite end of said means adapted to rollably engage said gripping members; and

3. an externally threaded portion disposed intermediate its ends adapted to threadably engage the internally threaded barre-l portion of said body so as to move said actuating means axially of said body.

8. An internal pipe wrench as defined in claim 7 in which the axes of the transverse bores formed in said wall are coplanar and are spaced apart approximately 9. An internal pipe wrench as defined in claim 7 ineluding means carried by said actuating means for engagement with said hollow body for preventing said actuating means from being threadably removed from said hollow body.

10. An internal pipe wrench for releasably gripping the internal wall of a length of tubing, comprising:

a. an elongated, hollow body having an annular wall provided with a plurality of transversely extending tapered bores therethrough, said body being adapted to be inserted into an open end of the tubb. a plurality of spherical gripping members rotatably carried by said tapered bores, said gripping members being axially movable within said tapered bores to extend radially outwardly beyond said wall; and

c. actuating means comprising a tapered member movably axially of said body into operable engagment with said gripping members for moving said gripping members radially outwardly within said tapered bores into gripping engagement with the walls of the tubing whereby the internal pipe wrench and the tubing can be rotated as a unit either in a clockwise or a counterclockwise direc- 

1. A gripping tool for gripping tubular objects, comprising: a. a hollow body adapted to be inserted into an open end of the tubular object, including a wall portion generally annular shaped in cross-section, said wall portion having a plurality of transverse bores extending therethrough; b. a plurality of generally spherically shaped gripping members carried within said transverse bores and movable axially thereof to protrude outwardly from said wall portion; and c. actuating means cooperatively associated with said body and movable relative thereto into operable engagement with said gripping members for moving said gripping members within said transverse bores in a radial direction with respect to said body whereby said gripping members are moved into gripping engagement with the tubular object to permit concomitant rotation thereof in either a clockwise or counterclockwise direction.
 2. A gripping tool as defined in claim 1 in which said actuation means comprises an elongated member receivable within said hollow body and axially movable relative thereto, said member having an inwardly tapering first end portion generally circular in cross-section at any point and so constructed that the outer surfaces thereof will operably engage said gripping members so as to urge them radially outwardly within the transverse bores upon movement of said actuating means axially of said body.
 2. a tapered portion disposed proximate and tapering inwardly toward the opposite end of said means adapted to rollably engage said gripping members; and
 2. an integral shank portion having a wall generally annular in shape at any point along its length;
 3. an externally threaded portion disposed intermediate its ends adapted to threadably engage the internally threaded barrel portion of said body so as to move said actuating means axially of said body.
 3. A gripping tool as defined in claim 2 in which said elongated member includes wrench engaging means provided proximate the end opposite the tapered portion thereof for engagement by a wrench adapted to impart rotation to said member.
 3. a plurality of transverse, tapered bores extending through said wall, said bores tapering from an enlarged cross-sectional diameter at a location proximate their inner ends to a reduced cross-sectional diameter at a location proximate their outer ends; and
 4. A gripping tool as defined in claim 2 in which said hollow body is internally threaded and in which said elongated member is provided with external threads intermediate its end portions adapted to threadably engage the internally threaded hollow body portion.
 4. wrench engaging means disposed externally of said barrel portion for engagement by a wrench adapted to impart rotational forces to said body; b. a plurality of generally spherically shaped gripping members carried by and movable axially within said transverse bores, said gripping members having a major diameter larger than the reduced cross-sectional diameter of the transverse bores; and c. an elongated actuating means movable axially of said body for urging said gripping members radially outwardly within the transverse bores in said wall, said actuating means having:
 5. A gripping tool as defined in claim 2 in which the transversely extending bores taper from an enlarged cross-sectional diameter at a point proximate their inner ends to a reduced cross-sectional diameter at a point proximate their outer ends.
 6. A gripping tool as defined in claim 5 in which the cross-sectional diameter of the transverse bores at a point proximate their inner ends is larger than the major diameter of said spherical gripping members and at a point proximate their outer ends is smaller than the major diameter of said spherical gripping members.
 7. An internal pipe wrench receivable into the open end of a length of pipe and adapted to releasably grip the internal Wall thereof for rotating the pipe to enable its connection with or removal from a mating part, said internal pipe wrench comprising: a. an elongated hollow body having:
 8. An internal pipe wrench as defined in claim 7 in which the axes of the transverse bores formed in said wall are coplanar and are spaced apart approximately 120*.
 9. An internal pipe wrench as defined in claim 7 including means carried by said actuating means for engagement with said hollow body for preventing said actuating means from being threadably removed from said hollow body.
 10. An internal pipe wrench for releasably gripping the internal wall of a length of tubing, comprising: a. an elongated, hollow body having an annular wall provided with a plurality of transversely extending tapered bores therethrough, said body being adapted to be inserted into an open end of the tubing; b. a plurality of spherical gripping members rotatably carried by said tapered bores, said gripping members being axially movable within said tapered bores to extend radially outwardly beyond said wall; and c. actuating means comprising a tapered member movably axially of said body into operable engagment with said gripping members for moving said gripping members radially outwardly within said tapered bores into gripping engagement with the walls of the tubing whereby the internal pipe wrench and the tubing can be rotated as a unit either in a clockwise or a counterclockwise direction. 